Die track for forming spiral steel tubing



J. FENTRESS.

`DIE TRAK OR FORMING SPIRAL STEEL TUBING. APPLICATION FILD JULY 14.1919.

hmmm@ Patented m2391922;

. 2 SHEETS-SHEET l I. AIENTRESS. DII;` TRACK FOR FORIVIING SPIRAL STEEL TUBING.

APPLICATION FILED JULY I4 I9I9.

Patented May 23, T922.

2 SHEETS-SHEET 2.

ybars the excess width can stick out` through the open edges of the bars Without interfering with the passage of the work as necessarily takes place Where the working tools are enclosed in blocks thicker than the working tools. Thelower die member 16 is provided with at least one discharge' notch spout 36 through which dirt or grease or the like' car- 'ried by the metallic strlp 12, on entering the die, may eject itself or be forcibly ejected and similar .discharge passages may be p rovided in the upper die member, one being indicated at 38, Figure 1.

It isobvious that to form cold flat parallel sided straight metal strip material into theV spiral tube of Figure 6, it is necessary that these members 16 and 18 be held rigidly spaced apart, as "shown in the drawings, 1t being well known inthe art that if die members are not so held serious trouble ensues. This result is accomplished by providing a base block or frame member 40 to which the Imember 16 is rigidly secured by any 'suitable means such, for instance, as the screws 42 and by providing a removable block 44 to which the die member 1 8 is rigidly attached by any suitable means as, for instance, the screw 46 and by then detachably securing block 44 to block 40 by suitable means such as a single screw 48. In the construction described, it isonly necessary to remove the screw 48 for the operator to move the parts of the die from the closed position of Figure 3 to separated position of Figure 4.

Figures/'1 and 2 of the drawings show the device of this invention heretofore described,

mounted in working position in the machine.,

i whiohiautomatically makes the tube. These figures show at the left, fragmentary portions of the last eedwheels 5() which drive holding the end 26 of the die mechanism in,

alinement with the wheels 52.

The die of thisinvention has been and is in commercial use and by actual test greatly reduces the cost of dies heretofore usedinmachines of his class; and greatly increases the eiliciency of the machine using the die,

both by increasing the speed of the machine and by reducing materially. time wasted in 'stoppages of the machine for trouble occuring in the die mechanism. The construction here shown has the advantage that the same die may be used for diierent sized tubes by changing the curvature .of bend 24. This can be effected by. annealing and bending slightly, then rehardening. Another ad'- vantage-is that the die is so thin that the rubi' ber 14.may be ted into the tube at the side of the point 26 of the die, while in old construc- 4tions it had to go through a hole, thus causing breaks in the rubber every time a knot came along.

The die is comparatively inexpensive because the main die parts being thin can be machine made while straight and then bent to the desired curve 24, while in prior conystructions formed in a thick block the track for the metal strip has to be dug by hand out of a solid block or it has to be made in additional parts fitted together, necessitating many diilicult adjustments.

Having thus described my-invention what I claim as new and desire to secure by Letters Patent,- isz- 1. In mechanism of the class described, two metal bars of considerable curved length and comparatively thin in one dimension, placed with their thin edges face to face. working surfaces for forming metal on said oppositely disposed thin faces and extending lengthwise of said metal bars, said working faces occupying substantially the whole of the thin opposing faces of the bar and means for rigidly securing said bars in vposition with reference to each other. i

2. In mechanism of the class described,

a pair of relativelv thin bars of substantial` length, placed edge to edge, there being formed upon the adjacent edges metal working tools spaced one from the other to shape a piece of metal passed longitudinally along between said bars, a curved bend in said bars sol that one end portion is at a substantial angle to the other end, and means for detachably securing said bars in said position with reference to each other.

3. In mechanism of the class described, a pair of relatively thin bars of substantial length, placed edge to edge, there being formed upon the adjacent edges metal working -tools spaced one from the other to shapia piece of metal passed longitudinally along between said bars, a curved bend in said ha rs so that one end portion is at a substantial angle to the other end` means for detachably securing said bars in said position with refer ence to each other, and guard rail mechanism adjacent to said curve for the purposes set forth.

4. In mechanism of the class desribed. a pair of relatively thin bars of' substantial length, placed edge to edge, there being formed upon the adjacent edges metal working tools spaced one from the other to shape a piece of metal passed longitudinally along between said bars, a curved bend in said bars so that one endportion is at a substantial angle to the other end, means for detachably securing said bars in said position with reference to each other, and a guard rail on the outside of said curve, for. the purposes set forth.

5. In mechanism of the class described, a

` ing tools spaced one Htl taranto pair ot relatively thin bars ot substantial length, placed ed e to ed e, there being formed upon the a jacent e ges metal worlrtrom the other tov shape a piece of metal passed longitudinally along between said bars, a curved bend in said bars so Vthat one end portion is at a substantial angle to the other end, means 'for detachably securing said bars in said position with reference to each other, and a guard rail on the inside-ot said curve tor the purposes set forth.

6. ln mechanisme. ol the class described, a pair ot relatively thin bars ot substantial length placed edge to edge, there being 'forme upon the a jacent edges metal worlring tools spaced one trom the other to shape .a piece ot metal passed longitudinally along between said bars, a curved bend in said bars so that one end portion is at a substantial angle to the other end, means tor detachably securing said bars in tion with reterence to each other, and guard rails on the inside and outside ot said bars tor the purposes set forth. y

"t, ln mechanism oit the class described, in combination with a supportin .base a relatively thin, lon curved bar, etachably secured to said ase, a supplemental block iitting on said base and detachably securable thereto, a second relatively thin long bar curved to contorm to the tlrst bar secured to .said snp lemental bloclr, said parte being; so arranged that the relatively thin edges oit .said bars closely approach each other but leave a space between them on which working surfaces tor forming a metal strip .are termed substantially the 'entire width ol the bars, the side edges 'ol said space between them being open t'or the purposes set torth.

8. ln mechanism ot the class dcribed, in combination with a supporting base, a relatively thin, long bar, detachably secured to said base, a supplemental block itting on said base and detachabl securable thereto, a second relatively thin on bar secured to said supplemental block, sai parts being so .arranged that the relatively thin edges ol said bars'closely approach each other but leave a space between them on which worlrsaid posiT i ing surlaces for termin a metalstrip are termed, the side edges o said space between them being open, there being a substantial bend in said bars beyond the supports, and guard rail mechanism adjacent to said bed tor preventingI the escape ot metal traveling around said bend in the working surfaces between said bars.

9. ln mechanism ot the class described, a die member comprising a air ol' relatively thin long bars correspon ingly curved intermediate ol their ends, each having a working surface intertting with the working surface ol the othensaid working surfaces ol the bars being placed `on the thin edges ot the respective bars and extending lengthwise ot the bars, and extending over substantially the entire width oi the bar whereby a metal strip passing between the bars lor torming thereby is constantly visible trom the outside or the bar.

10. ln mechanism of' the class described, a pair ot relatively thin long bars curved tor forming a strip ot metal, the thickness of the bars being substantially the thiclmess of the formed strip and the working surlaces for forming the strips `ol :metal being placed upon the thin edges ot the bar, and means lor rigidly detachably securing said lbars with their working iaces parallel to and separted trom each other, lor the purposes set forth.,

ll. ln mechanism ot the class described, a

die mechanism comprising 'a pair ot coin paratively long members correspondingly curved between their ends spaced apart one trom the other with worlring suriiaces -between them tor terminir metal passed rtherethrough along the length ot said bars, means for detachably securing the bars in said posi-- tion, said bars being ot such a dimension with reference to the worlr that exit .passages tor dirt are termed in one or both ol the bars leading trom the passage way to the sides oi the bars, tor the purposes set lorth.. n i y ln witness whereot, l have hereunto sub scribed my name. l

ranas rnn'rnnss.,

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